Direct-reading micrometer-caliper



` A. L. COLBURN. DIRECT READING MIGROMETER CALIPEB.

APPLICATION FIL-ED MAR. 4, |920.

Patented Aug. 30, 1921.

' type,'the object being to produce a simple,`

UNITED STATES PATENT oFFlcE.

ALBERT L. eoLBURN, or NEW HAVEN', CONNECTICT.

Specification of Letters Patent.

DIRECT-READING MicitoiviErER-CALIPER.

Patented Aug'. 30, 1921.

Application filed March 4, 1920. Serial No. 363,238.

ToaZZ whom it may concern .'r

Be it known that I, ALBERT L. COLBURN, a citizen of the United States, residing at New Haven, in the county of New Haven and State 0f Connecticut, have invented a new and useful Improvement in Direct- Reading "MicrometenCalipersg and l do hereby declare the following, when taken in connection with the accompanying drawl0y ings and the characters of Vreference marked thereon, to be a full, clear, and exact description of the same, and which said drawings" constitute part of this application, and represent, inf Figure l, a view in side elevation of a di.

longitudinal section, showing` the figure-A wheels and the gears for driving` the same; Fig. 5, an enlarged broken view thereof in central longitudinal section;

f Fig. 6,a detached plan view of the inter# nal ratchet feed wheel; y

Fig. 7, a detached view in side elevation of the coupling-screw; Y

Fig. 8, a reverse plan view thereof;

wheel 30 and the pinion 29 of the device;

Fig. 10, a corresponding view showing the intermittent-gears employed for operating the tens figure-wheel;

Fig. 11, a corresponding view of the inhundreds igurewheel; i

Fig. 12, a detached view showing` the intermittent-gears for operating the tens iigure-wheel when in their central position Y Fig. 13, a similar view showing the same wheels after their movement one thou sandth. of an'inch from the central position illustrated by thepreceding figure.

My invention relates to animproved micrometer caliper of the direct-reading convenient, and reliable direct-reading instrument constructed with particular reference to preserving in a directfreading caliper the familiar system ofgraduation used in ordinary. calipers, `to its'adaptation ,to be operated by one hand,-its ratchet-stop in-r cluded,to the fullliinit of its measuring cal to. take up p acity, to positiveness and accuracy of opera-k tion, and to ease of ladyus'tment to coinpensate for wear.

Tith these ends in view, my invention consists in a directreading micrometer 'caliper having certain'details of construction and combination of yparts as will be hereinafter described and pointed out in the claims. Y In carrying out my invention, I employ a bowed frame 2 mounting at its inner end an anvil 3 coperatingwith a normally non-rotatable spindle having'bearing and longitudinal movement in a flanged bushing 5 locatedin a'bearing-hole 6 Vin a housing 7 formed integral with the outer end of the bowed frame 2 aforesaid, the said bushing` being forced into the said hole but not tight enough topievent its being turned with the spindle and by the same when'it is desired wearbetween the spindle and the anvil. Y l

At its inner end, the non-rotatable spindle I 4 is provided" with a .threaded'head 8'0f forty threads to the inch. The said head 8 Vworks back and forth in a rotatable ibut non-reciprocal sleeve 9 internally threaded throughout its length. The outer end of the n pensatedV for by turningthe spindle by a Fig. 9, a detached view showing tlie'gearf wrench or other means.v whereby the spindle `is longitudinaily moved with respect to the Y tional form of the opening provided for it inV termittent-gears employed for operating the theiianged bushing 5, as shown in Fig. 3. The object of making the bushing rotatable isto perinitrtheV spindle to be turned forVV taking up wear as described. Y

the housing and formed with holes lO'Pfor the application of a spanner wrench by means of'gwhich it is removed .and replaced.` vThe inner face of the said nut provides abearing for the outer face of the main drivingf n' ,gear 12 of the device, the saidigear being formeches shown, by cutting teeth in the peripheryV of an annular shoulder made inf tegral with the sleeve 9,though if preferred,

theV gear may be made independently vofthe.,

sleeve and forced thereupon. In either case, the sleeve is held against longitudinal outward movement by the said nut, `while it is held against inward endwise movement by the bearing of its inner end upon the flanged inner end of the bushing 5, as shown in i ig. 5, wherebythe sleeve isheld against endwise movement in either direction, though lett free to rotate; whereas in the calipers of the prior art, the sleeve is mounted upon the spindle rather than journaled in the frame, and moves longitudinally, as well as rotates.

Upon the sleeve 9, I mount a graduated beveled collar or dial 13 positioned upon the sleeve so as to have bearing upon the outer tace of the nut 10 and the outer end of the housing 7 at av point thereupon around the threaded hole 11 formed therein for the reception of the nut 10, the said dial being formed with an integral outwardly extend-4 ing tapered split and externally threaded binding-collar 13qu mounting an internally threaded lrnurled binding-nut 14C by which the collar is firmly gripped upon the sleeve for rotation therewith.

The said dial 13 is encircled by graduations running .from zero to twenty-five, as required by the employment of forty threads to the inch upon the head 8 of the spindle 1. The graduations upon the dial are read in conjunction with a zero mark 14.n upon the front face of the housing 7 of the frame 2, as clearly shown in Fig. 1. By loosening the nut 14, the dial may be adjusted in its position upon the sleeve 9 so as to compensate for wear and so as to keep its graduations in absolutely correct relation to the Zero mark 149.

l may here state that standard calipers are generally constructed on the principle of forty pitch threads and twenty-five graduations, but I do not limit myself to this combination, as my device is .perfectly well adapted to other pitch ot threads and other systems of graduation.

At its outer end, the sleeve 9 mounts what is known in this art as a ratchet-stop mechanism for the reason that the caliper ceases to tunction as soon such mechanism begins to function. My improved ratchetstop comprises, as shown, a screwslug 15 the overhanging head 16 ot which holds an internal ratchet-feed wheel 17 against the "outer end of the said sleeve, as shown in Fig,

o. The said wheel 17 has a rounded knurled periphery somewhat larger in diameter than the diameter ,rot the sleeve; this is not necesary, though preferable: rThe internal ratchet-teeth 18 of the vsaid ratchet-feed wheel 17 are engaged by the nose or beveled outer end ot' a reciprocating pawl 19 setinto a hole 2() formed transversely in the outer' portion of the screw-plug 15 and also re-v ceiving a helical spring 21 which exerts ai constant 'eiort to force the nose of the pawl.

into engagement with the teeth 18. The said spring 21 is adapted in tension to hold the pawl 2O in engagement with the ratchetteeth 18 during the normal operation of the device, and only yields to permit the retirement ot the pawl when the force employed 'tor the rotation of the sleeve is great enough to endanger the springing of the bowed trame 2 and so destroying the utmost accuracy ot' n'ieasurement.

For the direct reading of measurements made by the instrument,`I employ three figure-wheels 22,23, and 24 of which the wheels 22 and 23 turn loosely upon the inner end of 'the sleeve 9, while the wheel 24: turns within an annular recess 25 oitsetting from the inner wall of the gear-chamber 26 ot' thehousor chambered head 7. The figure-wheels 22, 23, and 2a respectively indicate units of a! tl'iousandth, tens ot thousandths, and hun` ",vheel. The figure-wheels 23 and 24 are characterized by having their liguresarranged,

it may be said, in double sets running O 1 2 01 l, 2, periphery, making twenty figures in all, on each wheel. The novel arrangement is one oit the salient characteristics of my improved invention.

For driving these figure-wheels, the main iving-gear 12 .venty-one teeth and meshed into a pinion /7 having twelve teeth and mounted to turn oosely upon a 28 located in the lower Tiortion ot the gear-chamber 26 and jourled at Vits rear end in the inner wall of the 7, and at its opposite end in a removable plug 7u set into the housing. A pinion 29 oi iit'teen teeth is secured directly to the inner face Vot the pinion 27 by which it is revolved. The said pinion 29 meshes into a gear-wheel '30 of twenty-one teeth. The said gear 12, pinions 27 and 29, and gear 30, are employed to reduce the movement of the spindle and are made necessary by its provisions witha forty pitch thread.

The said gear-wheel is secured directly tothe outer tace of the iigurewheel 22 which is revolved by it, and the inner tace of which has secured to it an intermittent `gearwhce 31 star-gear l2 oi sit-:i double teeth turning loosely upon the'shatt 28 aforesaid and having secured to itsinnerface a pinion 33 ot nine teeth, which meshes into a gear-wheel i-l ot litt-een teeth, secured to the outer tace ot'. the figurefwheel 23 upon the inner face aforesaid, is provided with two teeth,A which meshes into a of which is secured an intermittent-gear 35 of one tooth meshingr into a star-wheel 36 of cured directly to the i'igure-wheel 24 which.,

is rotated by it.

The numerals upon the several ligurewheels 22,23, and 24 are exposed one at a `time through three sight-holes 39, 40,'and

l1" formed in the face ot' the housing 7. l

It will be seen, by reference to Figs. 10 and 11 that the intermittent gear-wheel 31 `and its star-wheel 32 and the intermittent gear-wheel 35 and itsstar-wheel 36 consti tute example-s of what is known asl the Grelneva stop-movement, this type of gearing'Y being self-locking andsecuring economy of space. e y

' The intermittent gear-wheels 31 and V35 are calculated on a basis of twenty teeth to ,the fullv circumferenre, while `the starfwheels 32 and 3G are calculated, as shown, onthe basis of twelve teeth to the full circumfer ence, though 'actually cut to provide s'iXr i in theory the same' number of teeth in the tullicircumference as there are Ynumerals onA the 'respective igurefwheels 22, 23, and 24,V

hmerals running from`1 to 10 on. the-4 double teeth. kHowever, the numberY of teeth in wheels 32 and 36 is, theoretically,-

immaterial so long as the number' is even.`

inasmuch as the wheels 31 and 35Y have the several numerals thereon representthousandths of an inch in the movementot the spindle 4; with respect to the anvil 3.

sit'ely located teeth of the gear-wheel 31 respectively respond to the double set ofl nu- ,f igure-wheel'22, while the double teeth of the star-wheels 32 and 36 respond to the novel complementarypairs of numerals have ing linear as well as seria-l arrangement kupon the ligure-wheels 23 andf2t.

ln the operation of my-improved caliper, the turning of the sleeve through ten .gradv nations on the graduated collar or dial 13 actuates the intermittent gear-wheel 31 inV a halt-rotation, whereby one of the two teeth of the wheel 31 co-'acts with one of the double teeth of the star-wheel 32 so as to 'relv volvo the same from one of its locked posi# tions to its next` locked position, the movementof the Wheel trom one lockedposition toV another being equivalent to a,move' ment of the spindle two'thousandths of an inch, due tothe fact that the'teethofithe Istar-wheel are *doubleY teeth.` This )movement of. the star-wheel 32 istransmitted by the pinion33 and wheel 34 to theligurewheel 23 which is rotatedtor a ,distancejrep- {iesentingtwo thousandths of an inch., ,During the movement of the wheel 23' tothe firstV In the syste'i'rn of gearing described, the two oppo-l tenths of an inch, one figure of one of its complementary pairsv of figures will be shown through the sight-hole 40. Thus, as shown. in Fig. 1, the numeral Ll appears in the sight-hole 40. At the same time, the 0 of one of the two sets of figures onr the wheel 22, appears through the sight-hole 39. At this time, the tooth of the wheel 31 in engagement with a tooth of the star-wheel '32, will be in line with a plane passing through theV axes of these `two wheels, as shown in Fig. 12. Now, as the wheel 32 is moved vby the wheel 31 from the central position in which it is shown in Fig.V 12, to the 'position in which it is shown in Fig. 13,'the

figure-wheel 23 is rotated for a distance representing one thousandth oi an inchwith the etl'ect of bringing the other 4 of its complementary pair of numerals fl into view tliroughthe sight-hole 40, while at the Sametime, the figure-wheel V22 has been correspondingly moved to bring the numeral 1 o'lz its same series of figures, to view through the sight-hole 39. The operation of the ligure-wheel 24 by the intermittentgear 35 and the star-wheel 3G-correspondsV to thefol'ierationjust described for the figrure-wheel 23.

f Y' SoV farY as thedirect-readng feature of my Vimproved caliper is concerned its salient though am not precluded from constructing my gear system to operate in l.conjuncftion with'a spindle having titty threads to the inch'.

Under my improved construction, the instrumentmaybe operated by one hand,

including its ratchet-stop, to the full limit of its measuring capacity, which is a matter of greatest convenience. I wish also to point Yout that under my construction, as the spindle does notrotate, there is no dangerV ol moving it in its manipulation so as to change" theset and destroy the measurement.

`I, claim:

1 A micrometer,caliper'having a trame,

an anvil, an externally,r threaded spindle mounted in the vsaid frame so as to'be' normally 'nonrotatable, but adapted *tov he turned by unusual force for taking up wear between it and the anvil, and a rotary sleeve Vhel d against endwise movement4 andr provided substantially `throughout its length with internal threads with which the threads of the spindle directly co-act.

2. A micrometer caliper having a frame, an anvil, a normally non-rotatable spindle having external threads, a rotary sleeve held against endwise movement and provided substantially throughout its length with inf ternal threads with which the threads of the spindle directly co-act, and mounting means for the spindle normally holding the same against rotation but turnable by unusual orce to permit the spindle to be turned to take up wear between the spindle and the anvil.

3. A micrometer caliper having a frame, an anvil, a bushing mounted in the said frame, a spindle sliding in the said bushing by which it is normally held against rotation and provided with external threads, and a rotary sleeve held against endwise movement and provided substantially through-out its length with internal threads with which the threads of the spindle directly co-act, the said bushing normally holding the spindle against rotation but yieldingly rotatable to permit the spindle to be turned to take up wear between it and the anvil.

4. A micrometer caliper having a frame,v

an anvil, a normally non-rotatable spindle provided at its inner end with an external head of larger diameter than the body of the spindle, a rotary sleeve held against endwise movemenet and provided substantially through-out its length with internal threads which directly co-act with the threaded head of the spindle, and mounting means for the spindle adapted to permit the same to be turned to compensate for wear between it and the anvil.

5. A micromeetercaliper having a frame, a normally non-rotatable spindle provided with external threads, a rotary sleeve provided substantially through-out its length with internal threads directly co-acting with the threads of the spindle, an annular bearing located upon the sleeve, a nut mounted in the frame and co-acting with the said bearing for preventing the endwise outward movement of the sleeve, and means for holding the sleeve against inward endwise movement. t

6. A micrometer caliper having a frame, a normally non-rotatable spindle having external threads, a rotary sleeve internally threaded substantially through-out Y'its length for direct engagement with the threads of the spindle, a main driving gear located upon the sleeve, a nut mounted in the frame and co-acting with the outside of the said gear forholding the sleeve against outward movement, and means for holding the sleeve against endwise inward movement.

7. A micrometer caliper having a frame, anvil, a normally non-rotatable spindle provided with external threads, a normally non-rotatable bushing mounted in the frame and providing a bearing for the spindle which it normally holds against rotation and by which it is turned when the spindle is turned to compensate for wear between it and the anvil, a rotary sleeve internally threaded for direct co-action with the threads of the spindle and bearing at its inner end against the said bushing, whereby it is held against endwise inward movement, and means for holding the sleeve against outward movement with respect to the frame.

8. A micrometer caliper having a frame, a non-rotary threaded spindle, a bushing mounted inthe frame and receiving the said spindle which is held against rotation by it, a rotary sleeve internally threaded for direct co-action with the spindle and journaled for rotation in the frame in which it is held y against endwise inward movement by the enuated dial adjustably mounted upon the sleeve on which it is positioned close to the said frame.

9. In a micrometer caliper, the combination with a frame, of a flanged bushing frictionally mounted therein, a spindleA passing through the said bushing by which it is held against rotation and having its inner end provided with threads, and a rotary sleeve journaled in the frame `and internally threaded for direct co-action with the threads of the spindle which is adjusted for wear by the bodily rotation of the bushing in the frame.

l0. A micrometer caliper having a frame, a normally non-rotatable externally threaded spindle, a sleeve internally threaded substantially throughout its length for direct co-action with the Said spindle, and a graduated collar adjustably mounted upon the sleeve for rotation therewith.

11. A micrometer caliper having a frame, a normally non-rotatable spindle having an externally threaded head, a sleeve held against endwise movement and provided substantially throughout its length with internal threads fordirectly co-acting with the threads of the said head of the spindle,'a graduated collar or dial formed with a split hub by means of which latter it is adjustably mounted directly upon the said sleeve, and ring-nut mounted upon, the said hub for grippingV the rsections thereof upon the sleeve.

'12. A direct-reading micrometer caliper having `a chambered frame, a normally, nonrotatable spindle having external threads, a rotary sleeve held against. endwise' movement and provided substantially throughout its length with internal threads for direct co-action With the threads of the Spindle a Wheel upon the said sleeve and direct-reading gear mechanism located Within the said frame and driven directly by the said Wheel.

13. A direct-reading micrometer caliper having a frame, a spindle, a sleeve for operating the same, and direct-reading mechanism including a. units figure-Wheel, a tens ligure-Wheel, a hundreds figure-Wheel, a Geneva stop-movement co-acting With the said units Wheel for operating the said tens Wheel, a Geneva stop-movement co-acting With the saidptens Wheel for operating the said hundreds Wheel, and gearing connecting the said sleeve with the said units Wheel for the operation of the same, the igures of the tens igure-Wheel and of the hundreds ligure- Wheel being arranged in pairs lineally and serially.

In testimony whereof, I have signed this specification in the presence of two subscribing Witnesses.

ALBERT L. COLBURN. Vitnesses GEO. D. SEYMOUR, J. HAROLD FLXNN. 

